Automatic firearm



May 1940. M. BIRKIGT AUTOMATIC FIREARM Filed April 1s, 193e 2 sheets-sheet 1 679507.- Mwa May 7 1940- M. BIRKIGT 2.199.872

AUTOMATIC FIREARM Filed April 16, 1938 2 Sheets-Sheet 2 ,f6 zg' 2.9 '25 11 H i U 1w! IVY/e all.' l i ,l II @t .i 21 N W W `L u@ if i K lx il lllh. 'Hl W *ii at. |l| [lim 11| ll" IW J Z 19 W 1l HWMAMMUJ i m nnnnnn 'j y 1a J2 f l 17 Ivg' /J (2Q/2a?! 'l 1W 21mm w ii Mln lu u millmml mi ;Z"`

Patented May 7, l

AUTOMATIC FIBEARM 'Mam irkigt, noia-colombes, France Application April 16, 1938, Serial No. 202,548

m Belgium February 17, 193s 'l Claims.

structure adapted to recoil after the firing of each f shot against the action of a counter spring;` This v movable breech structure includes two elements 10 movable axially relatively to each other. One of these elements constitutes the breech block proper and the other carries the firing pin. The breechv block is fitted with a pawl capable either of locking the two breech elements together, as long as l the breech block has not reached the .end of' its frontward stroke, or of locking said breech block with said gun (and especially the breech casing) when said breech block occupies said extreme frontward position, then simultaneously releasgo ing said iiring pin carrier from the breech block whereby said carrier can further move in the frontward direction so that the firing pin strikes the cartridge.

When, after this supplementary movement, the 5 firing pin carrier is returning backwardly towards the breech block, it must produce the disengagement of the breech block from the breech casing and the reengagement of the firing pin carrier with the breech block. In known de- 30 vices, this result is obtained by providing the pawl and the ring pin carrier with cooperating projections which produce the desired displacement of said pawl. But this arrangement has the disadvantage of producing violent shocks between these projections, which are soon worn after a relatively low number of shots has been red.

The object of the present invention is to provide a gun of the type above described which w avoids this drawback and is better adapted to meet the requirements of practice than similar guns made up to the present time.

According to the essential feature of the present invention, I provide, in the known manner, the firing pin carrier and the pawl carried by the breech block with corresponding projections adapted to cooperate together so as to ensure, at the time of the rearward movement of said carrier with respect to said breech block, a displacement of said pawl which disengages said breech block from locking engagement with the breech casing. But I also arrange the contacting surfaces of said pawl and said breech casing in such manner that the reaction of the thrust trans- 55 mitted between these parts has a transverse com- (ci. fief-s) ponent which also tends to produce the desired i movement of the pawl, and eiiectively causes this movement to take place as soon as said pawl ceases to be held in locking engagement with said casing. The various parts are so designed that this reaction of the pawl and the inclined surface of the casing takes place before the coop- 'erating projections of the fire pin carrier and the pawl have come into contact so that the shocks abovementioned are avoided. Under these conditions, said projections serve merely to oppose untimely jolts of the pawl, and also positively to produce the desired movement of the pawl when the whole of the movable breech structure is being moved toward the rear not by the recoil of l5 the gun but by an external energy applied to the ring pin carrier.

Other features of the present invention will result from the following detailed description of a specific embodiment thereof A preferred embodiment of the present invention will be hereinafter described with reference to the accompanying drawings, given merely by way of example, and in which:

Fig. l is an elevational view, partly in axial vertical section, of the breech mechanism of an automatic gun for an airplane made according to the present invention;

Fig. 2 is a sectional view on the line II-II of Fig. 1;

Fig. 3 is a partial vertical section on the line III-Ill of Fig. l;

Figs. 4, 5, 5' and 6 are detail views on an enlarged scale showing different relative positions of the parts of the breech mechanism, corresponding to different times of the operation thereof.

The barrel or tube l of the gun, made of any suitable type, carries. at the rear thereof, a breech casing 2 in which the breech block can slide with 40 a reciprocating motion. This casing 2 is provided at the top with a cartridge feeding slot 3 and at the bottom with a slot 4 for the ejection of the cartridge cases.

I'he movable breech structure slidable in this casing 2 is constantly urged in the forward direction by a counter-spring 5.

This breech structure includes two parts or elements 8 and 1 movable with respect to each 50 other in the axial direction of displacement of the whole.

Element S constitutes the breech block proper which forces and wedges the cartridges in the gun chamber when brought in its extreme frontf ward position which, in the reminder of the description, will be called firing position.

As for element I, it consists of two parallel bars, slidable on either side of the breech block and interconnected by a cross member `I,"slid able in the longitudinal direction in a transverse passage 6 provided in the breech block 6.

Element I carries a firing pin 9 mounted on cross member 1'.

reech block 6 carries a pawl 9, pivotally mounted thereon.

As long as the breech block is not in its ring position, this pawl 9 serves to lock elements 8 and I with respect to each other, said pawl being then in what will be called the upper position thereof, shown by Fig. 6.

When the breech block 6 reaches its firing position, pawl 9 is caused, preferably through the combined actions of a fixed projection I0, carried for instance by casing 2, and of an inclined surface I I carried by element 1, to come into a position (which will be hereinafter called lower position) in which its head is engaged and held in a notch I2 provided in casing Thus, the breech block is locked in firing position while element 'I is disengaged from with the breech block 6 and it can further move a short distance in the forward direction under the effect of its inertia and counter-spring 5, so that the firing pin strikes the cartridge and the shot is fired (position shown by Fig. 4).

Preferably, between elements 6 and 'I of the breech structure, I provide spring means such as r urging element I in the frontward direction with respect to element 6.

Immediately upon the firing of each shot, breech element 'I is to be moved back toward the rear with respect to the breech block 6, so that these two elements` can again come into locking engagement with each other. This initial backward movement of element 'I is ensured, in the embodiment shown by the drawing, by a piston and cylinder system IS-I 4, operative by the burnt powder gases in the gun bore, and which transmits its movement to element 1 through a push piece I5.

Preferably, the gun is provided with cooking means, that is to say means for drawing the movable breech structure fully back through the action of an external energy (compressed air for instance) when this has not occurred by itself in the course of the operation of the gun, for instance as a consequence of a misflre. Said cooking means may include, for instance, as shown by the drawing, a cylinder I6 provided on the side of casing 2, a piston I'I movable in said cylinder under the action of compressed air, and a finger I8 rigid with one of the bars of element 1, adapted to be pushed rearwardly by said plston.

I will now describe in detail the means for switching pawl 9 from its lower into its upper position after the ring of each shot.

As already explained, these means include an inclined surface I9, forming the front inner wall of the notch provided in element 1, adapted to coact, near the end of the backward movement of element 1 with respect to breech block 6, with a projection 20 carried by pawl, these cooperating surfaces tending to produce an upward pivoting of the pawl.

According to the essential feature of my invention, the contacting surfaces 9' and I2' along which pawl 9 and the edge of notch I2 bear against each other are so inclined with respect to the direction of the thrust exerted by pawl 9 (under the effect of the explosion of the powder charge in the gun) on casing 2, that the reaction of surface I2 has a transverse component which tends to push the head of pawl 9 out from notch I2 in the upward direction. Therefore pawl 9 is driven into its upper position as soon as the notch in member 'I comes above it and permits this movement, that is to say practically before the inclined surface I9 has come into contact with projection 20 (intermediate position of Fig. 5).

It will be readily understood that, with such an arrangement, I avoid the violent shocks between said inclined surface and said projection which might damage these parts, as it wasy the case when the movement of pawl was produced directly and solely by the 'cooperation of said parts as in the prior practice. The inclined surface I9, which is engaged under projection 29 as pawl 9 is being switched to its upper position serves merely to prevent said pawl 9 from rebounding against the bars of element 'I.

After the return of pawl 9 into its upper position (as shown by Fig. 6), there exists between inclined surface I9 and projection 20 a certain clearance which is maintained by the fact that springs 1' constantly urge element I toward the front with respect to the breech block 9.

When the backward movement of element 'I,

instead of taking place in the course of the opp eration of the gun, is produced by the working of the cocking device above mentioned, the breech block 6 and consequently pawl 9 do not undergo a backward thrust as in the above described operation. There is no transverse reaction component from inclined surface I2 tending to move pawl 9 into its upperposition. In this case, during the backward movement of element I produced by the cooking device, inclined surface I9 comes into contact with projection 29 of the pawl, thus causing said pawl to pivot upwardly (Fig. 5') so as to uncouple element 6 and casing 2, and on the contrary to lock elements 6 and 'I together. But this direct action of inclined surface I9 on projection 20 is without inconvenience because in this case the partsI are not moving at high speed and besides this operation is exceptional.

To sum up, the essential advantages of the breech mechanism according to the present invention are the following:

Inclined surface I9 and projection 20 are protected against violent shocks such as would occur if these parts cooperated directly with each other at the time of the recoil of the breech block produced by the firing of a shot. l

'Ihese parts however prevent objectionable jolts of pawl 9 and in particular prevent it from rebounding on element 1.

Finally parts I9 and 20 ensure the operation of pawl 9 in a positive manner when the movable breech structure is being moved rearwardly by an external energy, such as the cooking device above described.

In a general manner, while I have, in the above description, disclosed what I deem to be practical and eflicient embodiments of the present invention, it should be well understood that I do not wish to be limited thereto as there might be changes made in the arrangement, disposition, and form of the parts without departing from the principle of the present Ainvention as comprehended within the scope of the ap- Dended claims.

What I claim is:

1. An automatic firearm which comprises. in combination, a tube, a breech structure movable with a reciprocating motion in line with said tube at the rear thereof, a stationary casing rigid with said tube for guiding said breech structure. said breech structure including a breech block proper and a ring pin carrier movable longitudinally to a limited extent with respect to said breech block, a pawl movably carried by said breech block, said firing pin carrier being provided with a notch adapted to cooperate with said pawl for interlocking said breech block and said rlng pin carrier, said casing being provided with a notch adapted to cooperate with said pawl for locking it with respect to said casing at the end of its frontward stroke, and simultaneously unlocking said fire pin carrier from said breech block, whereby said iire pin carrier is free to move further toward the front a distance suflicient for the percussion of the cartridge, first means for resiliently driving said ring pin carrier toward the front, second means for driving said iiring pin carrier backwardly immediately upon the firing of a shot, contacting surfaces on said pawl and said casing said contacting surfaces being so inclined with respect to each other and to the direction of the thrust as to produce a transverse reaction component, whereby to drive said pawl into said first mentioned notch when, in the course of the return stroke of said firing pin carrier with respect to said breech block, said first mentioned notch comes opposite said pawl, and third means operative independently of said contacting surfaces comprising cooperating inclined projections carried by said firing pin carrier and said pawl respectively for actuating said last mentioned movement of said pawl upon the return stroke of said firing pin carrier said carrier means being so, adapted and arranged as to produce this last mentioned displacement of said pawl when said displacement is not produced by the reaction of the contacting surfaces of said pawl and the second mentioned notch.

2. An automatic rearm which comprises, in combination, a tube, a breech structure movable with a reciprocating motion in line with said tube at the rear thereof, a stationary casing rigid with said tube for guiding said breech structure,

said breech structure including a breech block proper and a firing pin carrier movable longitudinally to a limited extent with respect to said breech block, a pawl pivoted at its front end to said breech block, said tiring pin carrier being provided with a notch adapted to cooperate with the rear end of said pawl for interlocking said breech block and said firing pin carrier, a counter-spring arranged to urge said iiring pin carrier toward the front with respect to said casing, said casing being provided with a notch adapted to cooperate with said pawl for locking said breech block with respect to said casing at the end of its frontward stroke and simultaneously unlocking said firing pin carrier from said breech block, whereby said firing pin carrier is free to move further toward the front under the effect of said counter-spring, for ensuring percussion of the cartridge, first means for driving back said firing pin carrier in the rearward direction immediately upon the firing of a shot, contacting surfaces on said pawl and said casing, said contacting surfaces being so inclined with respect to each other and to the direction of the thrust transmitted from one to the other as to produce said breech block and said iiring pin carrier for a transverse reaction component, whereby to drive said pawl into said first mentioned notch when, in the course of the return stroke of said firing pin carrier with respect 4to said breech block, said rst mentioned notch comes oppo- 5 site said pawl and second means, operative independently of said contacting surfaces comprising, cooperating projections carried by said firing pin carrier and said pawl respectively for accompanying this last mentioned movement of said pawl upon the return stroke of said ring pin-carrier and spring means interposed between constantly urging said firing pin carrier toward the front with respectV to said breech block, said cooperating projections of said'iirng pin carrier and said pawl being so positioned on said two respective parts as to beheld at a small interval from each other when said pawl is engaged in the iirst mentioned notch, under the in fluence of the last mentioned spring means.

3. An automatic firearm which comprises, in combination, a tube, a breech structure movable with a, reciprocating motion in line with said tube at the rear thereof, a stationary casing rigid with said tube for guiding said breech structure, said breech structure including a breech block proper and a ring pin carrier movable longitudinally to a limited extent with respect to said breech block, a pawl pivoted at its front end to said breech block, said firing pin carrier being provided with a notch adapted to cooperate with the rear end of s aid pawl for interlocking said breech block and said firing pin carrier, a counter-spring arranged to urge said ring pin carrier toward the front with respect to said casing, said casing being provided with a notch adapted to cooperate with said pawl for locking said breech block with respect to said casing at the end of its frontward stroke and to simultaneously unlock said firing pin carrier from said breech block, Whereby said ring pin carrier is free to move further toward the front under the eiect of said counter-spring. for ensuring the percussion of the cartridge, first means for driving back said firing pin carrier in the rearward direction immediately upon the iiring of a shot, contacting surfaces on said pawl and said casing, said contacting surfaces being so inclined with respect to each other and to the direction of the thrust transmitted from one to the other as to produce a transverse reaction component, whereby to drive said pawl into said first mentioned notch when, in the course of the return stroke of said firing pin carrier with respect to said breech block, said first mentioned notch comes opposite said pawl, a cocking device for moving said ring pin carrier backwardly against the action of said counter-spring by means of an external source of energy, and second means operative independently of said contacting surfaces, comprising cooperating inclined projections carried by said iiring pin carrier and said pawl respectively for actuating this last mentioned movement of said pawl produced upon the return stroke of the ring carrier with respect to the breech block by the coaction of said pawl and said second mentioned notch, said inclined projections being adapted to produce by themselves positively the last mentioned movement of said pawl in response to a backward movement of said firing pin carrier produced by the operation of said cooking device.

4. An automatic irearm according to claim 3 75 in which said cooking device is of the pneumatic type.

5. An automatic firearm according to claim 3 in which said cooking device includes a cylinder fixed to one side of the breech casing, and parallel thereto, a pistonmovable in said cylinder said piston being operative? by compressed air, and means for connecting said piston with said firing pin carrier when said piston is moving in the rearward .direction of the firearm.

6. An automatic firearm which comprises, in combination, a tube, a breech structure movable with a reciprocating motion in line with said tube at the rear thereof, a stationary casing rigid with said tube for guiding said breech structure, said breech structure including a breech-block proper and a firing pin carrier movable longitudinally to a limited extent with respect to said breech block, a pawl movably carried by said breech block, said firing pin carrier being provided with a notch adapted to cooperate with' said pawl for interlocking said breech block and said firing pin carrier, said casing being lprovided with a notch adapted to cooperate with said pawl for locking it with respect to said casing at the end of its frontward stroke and simultaneously unlocking said firing pin carrier from Said breech block, whereby said firing pin carrier is free to move further toward the front a distance suiiicient to the percussion of the cartridge, first means for resiliently driving said firing pin carrier toward the front, second means for driving said firing pin carrier backwardly immediately upon the iiring of a shot, contacting surfaces on said pawl and said casing, said contacting Surfaces being so inclined with respect to each other and to the direction of the thrust as to produce a transverse reaction component, whereby to drive said pawl into said rst mentioned notch when, in the course of the return stroke of said firing pin carrier with respect to said breech block, said first mentioned notch comes opposite said pawl, and third means comprising a first abutment carried by said firing pin carrier and a second cooperating abutment carried by said pawl, said abutments being so adapted and arranged that, after said pawl has been driven into said first mentioned notch by the reaction produced by aforesaid contacting surfaces, the backward movement of said firing pin carrier brings said first abutment in the way of said second abutment so as to prevent the block proper and a ring pin carrier movablev longitudinally to a limited extent with respect to said breech block, a pawl movably carried by said' breech block, said firing pin carrier being provided with a notch adapted to cooperate with said pawl for interlocking said breech block and saidfiring pin carrier, said casing being provided with a notch adapted to cooperate with said pawl for locking it with respect to said casing at the end of its frontward stroke and simultaneously unlocking said firing pin carrier from said breech block, whereby said firing pin carrier is free to move further toward the front a distance suiiicient for the percussion of the c-artridge, first means for resiliently driving said firing pin carrier toward the front, second means for driving said firing pin carrier backwardly immediately upon the ring of a shot, contacting surfaces so inclined with respect to each other and to the direction of the thrust as to produce a transverse reaction component, whereby to drive said pawl into said first mentioned notch when, in the course of the return stroke of said ring pin carrier with respect to said breech block, said first mentioned notch comes opposite said pawl, and third means operative independently of said contacting surfaces comprising cooperating inclined projections carried by said ring pin carrier and said pawl respectively, said third means being so adapted and so arranged that after said pawl has been driven into said rst mentioned notch by the reaction produced by aforesaid contacting surfaces, the backward movement of said ring pin carrier brings the inclined projection carried by said ring pin carrier in the way of the inclined projection carried by said pawl so as to prevent the rebound of said pawl out of said rst mentioned notch and, moreover, so adapted and so arranged as to produce this last mentioned displacement of said pawl when said displacement is not produced by the reaction of said contacting surfaces.

MARC BIRKIGT. 

